Neural networks and blood cell identification

The objective of this project is to propose a method of identifying cells found in human blood and to classify them based upon their morphological features using neural networks. The project focuses on three major blood cell types, namely, erythrocytes, leukocytes and platelets. The data are collected using peripheral blood smears from clinical patients. The image acquisition requires 100x magnification on all the blood smears, the preprocessing involves the use of median and edge enhance filters; the feature extraction is done by performing the wavelet transform on the images. Finally classification of the blood cell types is done using ALOPEX and Back Propagation trained neural networks. The efficacy of both networks is then compared by comparing their outputs and number of iterations required to reach the final result.     

Amyloid beta-protein deposition in the leptomeninges and cerebral cortex

To further investigate the process of amyloid beta-protein (Abeta) deposition, we determined, using sensitive enzyme immunoassays, the levels of Abeta40 and Abeta42 (Abetas) in the soluble and insoluble fractions of the leptomeninges (containing arachnoid mater and leptomeningeal vessels) and cerebral cortices from elderly control subjects showing various stages of Abeta deposition and from patients affected by Alzheimer's disease (AD). In both locations, insoluble Abeta levels were higher by orders of magnitude than soluble Abeta levels. Soluble Abeta levels in cortices were much lower than those in leptomeninges. In insoluble Abeta in the cortex, Abeta42 was by far the predominant species, and Abeta42 in AD cortices was characterized by the highest degree of modifications in the amino terminus. In contrast, this Abeta42 predominance was not observed in insoluble Abeta in the leptomeninges, which were found to be able to accumulate Abetas to an extent similar to that in the cortex, on a weight basis. The levels of insoluble Abeta in the leptomeninges or cortex generally correlated with the degree of cerebral amyloid angiopathy or the abundance of senile plaque, respectively. However, the presence of plaque-free cortical samples showing significant levels of insoluble Abeta42 suggests that biochemically detectable Abeta accumulation precedes immunocytochemically detectable Abeta deposition in the cortex.     

Passive sensitization of human airways induces myogenic contractile responses in vitro

We assessed effects of passive sensitization on human bronchial smooth muscle (BSM) response to mechanical stretching in vitro. Bronchial rings were sham (control) or passively sensitized overnight by using sera from donors demonstrating sensitivity to Dermatophagoides farinae and having immunoglobulin E (IgE) concentrations of 2,600 +/- 200 U/ml. Tissues were fixed isometrically to force transducers to measure responses to electrical field stimulation (EFS) and quick stretch (QS). The myogenic response to QS was normalized to the maximal response to EFS (%EFS). The myogenic response of sensitized BSM was 47.9 +/- 10.9 %EFS to a QS of approximately 6.5% optimal length (Lo); sham-sensitized tissues had a myogenic response of 13.5 +/- 6.4 %EFS (P = 0.012 vs. passively sensitized). A QS of approximately 13% Lo in sensitized BSM caused a response of 82.8 +/- 20.9 %EFS; sham-sensitized tissues developed a response of 38.2 +/- 17.3 %EFS (P = 0.004). BSM incubated with serum from nonallergic donors did not demonstrate increased QS response (4.6 +/- 1.4 %EFS, P = not significant vs. tissue exposed to atopic sera). However, tissues incubated in sera from nonatopic donors supplemented with hapten-specific chimeric IgE (JW8) demonstrated augmented myogenic response to QS of approximately 6.5% Lo (21.9 +/- 6.2 %EFS, P = 0. 027 vs. nonatopic sera alone). We demonstrate that passive sensitization of human BSM preparations causes induction and augmentation of myogenic contractions to QS; this hyperresponsiveness corresponds to the IgE concentration in sensitizing sera.     

Comparison of the biodistribution and the efficacy of monoclonal antibody 323/A3 labeled with either 131I or 186Re in human ovarian cancer xenografts

The effects of arginine vasopressin (AVP) and oxytocin (OT) upon thyroid-stimulating hormone (TSH), free thyroxine (FT4) and free triiodothyronine (FT3) release were studied in euthyroid rats. Intracerebroventricular (i.c.v.) infusion of AVP in doses of 0.5 ng or 5 ng led to significant increases in plasma levels of TSH as well as FT4 and FT3. The effects of OT injected i.c.v. in similar doses were not consistent (there was no parallel between the changes of respective hormones plasma levels). It may be concluded that vasopressin modulate the pituitary-thyroid system function; AVP is probably a physiological stimulator of TSH and thyroid hormones secretion.     

Analysis of distribution of Campylobacter jejuni and Campylobacter coli in broilers by using restriction fragment length polymorphism of flagellin gene

The incidence of Campylobacter jejuni and Campylobacter coli in broiler farms was 33.9% (19/56). C. jejuni-positive flocks accounted for 20.0% (17/85) and C. coli-positive ones was 4.7% (4/85). There were 14 patterns (fla type) of restriction fragment length polymorphism (RFLP) of flagellin A gene among these 22 strains of C. jejuni and C. coli including the standard strain C. jejuni ATCC 33560. Different fla types of Campylobacter were isolated from broilers in different growing cycles on the same farms. Four strains of C. jejuni were isolated from four breeder farms and four fla types of C. jejuni were detected from their progenies reared on growing farms. Three fla types of C. jejuni detected from the progenies were different from those of each breeder. Also, the other three fla types of C. jejuni were detected from different progenies of each growing farm during the next growing cycle. These findings indicate that the RFLP analysis may contribute to epidemiological studies of C. jejuni and C. coli contamination of broilers and suggest the risk of contamination with different types of Campylobacter in every growing cycle of broilers on the farm even on the same farm. They also supported that there was little likeliness of the vertical transmission of C. jejuni and C. coli from breeders to broilers.     

Perturbation in the 240Pu/239Pu global fallout ratio in local sediments following the nuclear accidents at Thule (Greenland) and Palomares (Spain)

Diabetes complicates 2-3% of all pregnancies and is associated with an increase in both perinatal morbidity and mortality, though reasons for these adverse outcomes are unknown. Estrogen biosynthesis is a critical factor during pregnancy and is carried out in the placenta via aromatase (cytochrome P450 19A1), which catalyzes the conversion of C-19 androgens to C-18 estrogens. Previous studies have shown that hormones such as insulin-like growth factors and insulin regulate aromatase activity when studied in vitro. Interestingly, levels of these hormones are altered in patients with diabetes. Thus, we hypothesized that the presence of maternal diabetes may alter placental aromatase activity and thus estrogen biosynthesis, possibly serving as one factor in the adverse outcomes of babies born to mothers with diabetes. To this end, we measured the production of 19-hydroxyandrostenedione, 19-oxoadrostenedione and estrone in 30 placental tissues from diabetic patients, using [7-3H]androst-4-ene-3,17-dione as a model substrate for aromatase (P450 19A1). A statistical difference was detected in the percentage of 19-oxoandrostenedione formed between the overt and control groups (P < 0.05). Additionally, NADPH P450-reductase levels were measured in these same tissues to determine whether alterations in this enzyme necessary for aromatase activity could be affected by diabetes. No differences in reductase levels were detected among the patient groups. However, a statistical correlation was found between NADPH P450-reductase activity and the formation velocities of all three estrogen products (P < 0.05). Thus, it appears that the presence of diabetes does not affect placental aromatase activity.     

From particle-mass to multibody systems: graph-theoretic modeling

The distinction between geometry and dynamic interactions is fundamental for the consistent dynamic analysis of physical systems. A unified treatment of such systems is possible when we adopt a hierarchical mathematical model with a consistent set of embedded abstractions. This new view is adopted in the general formulation strategy for obtaining a simplified dynamics model of mechanical systems. We show that there exists a consistent general extension from the model of constrained particle-mass systems (PMS) to the model of multibody systems (MBS) based entirely on graph-theoretic concepts     

Globally convergent edge-preserving regularized reconstruction: anapplication to limited-angle tomography

We introduce a generalization of a deterministic relaxation algorithm for edge-preserving regularization in linear inverse problems. This algorithm transforms the original (possibly nonconvex) optimization problem into a sequence of quadratic optimization problems, and has been shown to converge under certain conditions when the original cost functional being minimized is strictly convex. We prove that our more general algorithm is globally convergent (i.e., converges to a local minimum from any initialization) under less restrictive conditions, even when the original cost functional is nonconvex. We apply this algorithm to tomographic reconstruction from limited-angle data by formulating the problem as one of regularized least-squares optimization. The results demonstrate that the constraint of piecewise smoothness, applied through the use of edge-preserving regularization, can provide excellent limited-angle tomographic reconstructions. Two edge-preserving regularizers-one convex, the other nonconvex-are used in numerous simulations to demonstrate the effectiveness of the algorithm under various limited-angle scenarios, and to explore how factors, such as the choice of error norm, angular sampling rate and amount of noise, affect the reconstruction quality and algorithm performance. These simulation results show that for this application, the nonconvex regularizer produces consistently superior results.